TIIALLOPriYTES; FUNOI 



287 



lias a stalk-liki' povtioii, the sfljic^ at the base of which the 

 sleniler mycelial threads look like white rootlets; ajid an 

 expanded, undjrella-like top called the jjileu.s. From the 

 under surface of the pileus there hang thin radiating plates, 

 or gills (Fig. 255), Eacli gill is a mass of interwoven fila- 

 ments (hyphfe), whose tips turn toward the surface and 

 form a compact layer of end cells (Fig. 256). These end 



Fig. '3fj0. A bracket fungus {Poly porn -<) growing on the trunk of a red oak.- 



C'ALDWELL. 



cells, forming the surface of the gill, are cluh-sliaped, and 

 are called Jxtsidia. From the broad end of each basidium 

 two or four delicate branches arise, each bearing a minute 

 spore, Tcry much as the sporidia appear in the wheat rust. 



